Merge pull request toptal#180 from seejohnrun/es6_generators

ES6 generators

lib/key_generators/dictionary.js

@@ -1,24 +1,32 @@
-var fs = require('fs');
-
-var DictionaryGenerator = function(options) {
-  //Options
-  if (!options) throw Error('No options passed to generator');
-  if (!options.path) throw Error('No dictionary path specified in options');
-
-  //Load dictionary
-  fs.readFile(options.path, 'utf8', (err, data) => {
-    if (err) throw err;
-    this.dictionary = data.split(/[\n\r]+/);
-  });
-};
+const fs = require('fs');
 
-//Generates a dictionary-based key, of keyLength words
-DictionaryGenerator.prototype.createKey = function(keyLength) {
-  var text = '';
-  for(var i = 0; i < keyLength; i++)
-    text += this.dictionary[Math.floor(Math.random() * this.dictionary.length)];
+module.exports = class DictionaryGenerator {
 
-  return text;
-};
+  constructor(options, readyCallback) {
+    // Check options format
+    if (!options)      throw Error('No options passed to generator');
+    if (!options.path) throw Error('No dictionary path specified in options');
+
+    // Load dictionary
+    fs.readFile(options.path, 'utf8', (err, data) => {
+      if (err) throw err;
+
+      this.dictionary = data.split(/[\n\r]+/);
+
+      if (readyCallback) readyCallback();
+    });
+  }
 
-module.exports = DictionaryGenerator;
+  // Generates a dictionary-based key, of keyLength words
+  createKey(keyLength) {
+    let text = '';
+
+    for (let i = 0; i < keyLength; i++) {
+      const index = Math.floor(Math.random() * this.dictionary.length);
+      text += this.dictionary[index];
+    }
+
+    return text;
+  }
+
+};

lib/key_generators/phonetic.js

@@ -1,33 +1,27 @@
 // Draws inspiration from pwgen and http://tools.arantius.com/password
-var PhoneticKeyGenerator = function() {
-  // No options
-};
 
-// Generate a phonetic key
-PhoneticKeyGenerator.prototype.createKey = function(keyLength) {
-  var text = '';
-  var start = Math.round(Math.random());
-  for (var i = 0; i < keyLength; i++) {
-    text += (i % 2 == start) ? this.randConsonant() : this.randVowel();
-  }
-  return text;
+const randOf = (collection) => {
+  return () => {
+    return collection[Math.floor(Math.random() * collection.length)];
+  };
 };
 
-PhoneticKeyGenerator.consonants = 'bcdfghjklmnpqrstvwxyz';
-PhoneticKeyGenerator.vowels = 'aeiou';
+// Helper methods to get an random vowel or consonant
+const randVowel = randOf('aeiou');
+const randConsonant = randOf('bcdfghjklmnpqrstvwxyz');
 
-// Get an random vowel
-PhoneticKeyGenerator.prototype.randVowel = function() {
-  return PhoneticKeyGenerator.vowels[
-    Math.floor(Math.random() * PhoneticKeyGenerator.vowels.length)
-  ];
-};
+module.exports = class PhoneticKeyGenerator {
 
-// Get an random consonant
-PhoneticKeyGenerator.prototype.randConsonant = function() {
-  return PhoneticKeyGenerator.consonants[
-    Math.floor(Math.random() * PhoneticKeyGenerator.consonants.length)
-  ];
-};
+  // Generate a phonetic key of alternating consonant & vowel
+  createKey(keyLength) {
+    let text = '';
+    const start = Math.round(Math.random());
 
-module.exports = PhoneticKeyGenerator;
+    for (let i = 0; i < keyLength; i++) {
+      text += (i % 2 == start) ? randConsonant() : randVowel();
+    }
+
+    return text;
+  }
+
+};

lib/key_generators/random.js

@@ -1,19 +1,20 @@
-var RandomKeyGenerator = function(options) {
-  if (!options) {
-    options = {};
+module.exports = class RandomKeyGenerator {
+
+  // Initialize a new generator with the given keySpace
+  constructor(options = {}) {
+    this.keyspace = options.keyspace || 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';
   }
-  this.keyspace = options.keyspace || 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';
-};
 
-// Generate a random key
-RandomKeyGenerator.prototype.createKey = function(keyLength) {
-  var text = '';
-  var index;
-  for (var i = 0; i < keyLength; i++) {
-    index = Math.floor(Math.random() * this.keyspace.length);
-    text += this.keyspace.charAt(index);
+  // Generate a key of the given length
+  createKey(keyLength) {
+    var text = '';
+
+    for (var i = 0; i < keyLength; i++) {
+      const index = Math.floor(Math.random() * this.keyspace.length);
+      text += this.keyspace.charAt(index);
+    }
+
+    return text;
   }
-  return text;
-};
 
-module.exports = RandomKeyGenerator;
+};

package.json

@@ -46,6 +46,6 @@
   },
   "scripts": {
     "start": "node server.js",
-    "test": "mocha"
+    "test": "mocha --recursive"
   }
 }

test/key_generators/dictionary_spec.js

@@ -0,0 +1,33 @@
+/* global describe, it */
+
+const assert = require('assert');
+
+const fs = require('fs');
+
+const Generator = require('../../lib/key_generators/dictionary');
+
+describe('RandomKeyGenerator', function() {
+  describe('randomKey', function() {
+    it('should throw an error if given no options', () => {
+      assert.throws(() => {
+        new Generator();
+      }, Error);
+    });
+
+    it('should throw an error if given no path', () => {
+      assert.throws(() => {
+        new Generator({});
+      }, Error);
+    });
+
+    it('should return a key of the proper number of words from the given dictionary', () => {
+      const path = '/tmp/haste-server-test-dictionary';
+      const words = ['cat'];
+      fs.writeFileSync(path, words.join('\n'));
+
+      const gen = new Generator({path}, () => {
+        assert.equal('catcatcat', gen.createKey(3));
+      });
+    });
+  });
+});

test/key_generators/phonetic_spec.js

@@ -0,0 +1,27 @@
+/* global describe, it */
+
+const assert = require('assert');
+
+const Generator = require('../../lib/key_generators/phonetic');
+
+const vowels = 'aeiou';
+const consonants = 'bcdfghjklmnpqrstvwxyz';
+
+describe('RandomKeyGenerator', () => {
+  describe('randomKey', () => {
+    it('should return a key of the proper length', () => {
+      const gen = new Generator();
+      assert.equal(6, gen.createKey(6).length);
+    });
+
+    it('should alternate consonants and vowels', () => {
+      const gen = new Generator();
+
+      const key = gen.createKey(3);
+
+      assert.ok(consonants.includes(key[0]));
+      assert.ok(consonants.includes(key[2]));
+      assert.ok(vowels.includes(key[1]));
+    });
+  });
+});

test/key_generators/random_spec.js

@@ -0,0 +1,19 @@
+/* global describe, it */
+
+const assert = require('assert');
+
+const Generator = require('../../lib/key_generators/random');
+
+describe('RandomKeyGenerator', () => {
+  describe('randomKey', () => {
+    it('should return a key of the proper length', () => {
+      const gen = new Generator();
+      assert.equal(6, gen.createKey(6).length);
+    });
+
+    it('should use a key from the given keyset if given', () => {
+      const gen = new Generator({keyspace: 'A'});
+      assert.equal('AAAAAA', gen.createKey(6));
+    });
+  });
+});